Method of using V-clamp installation tool

ABSTRACT

An apparatus for seating and tightening clamps around joints between tubular sections comprises an elongate flexible member such as a chain for extending around a clamp positioned over a joint, the member having rollers spaced along its length, and a tightening device for applying tension to the member to tighten it around the clamp so that the rollers roll around the surface of the clamp and apply a radial force to the clamp.

The government has rights to this invention pursuant to Contract No.N00024-79-C-5202.

BACKGROUND OF THE INVENTION

The present invention relates to an apparatus or tool for seating andtightening clamps around joints between tubular sections, for examplebetween adjacent missile sections, on pumps, motors, or on pipelinesections.

Clamps for joining two adjacent tubular sections are generally known asV-clamps and generally consist of a V-section ring or sleeve whichextends over the joint and has a tightening bolt for tightening theclamp over the joint. Presently, such clamps are tightened by tappingthe ring with a mallet and then tightening the clamp bolt, repeating theprocedure until the clamp bolt shows no sign of movement. This tappinginduces shock and vibration into the item being joined and also reducesthe life of the clamp ring. This method also does not achieve an evenlydistributed load around the V-clamp as it is tightened, so that theclamp may not be seated uniformly.

SUMMARY OF THE INVENTION

It is an object of this invention to provide a tool which can staticallyseat V-clamps.

According to the present invention an apparatus for seating andtightening V-clamps around joints is provided, which comprises anelongate flexible member with a plurality of rollers spaced along itslength for extending around a V-clamp positioned over a joint, and atightening device for tightening the member around the clamp. Therollers are positioned to roll around the surface of the clamp as themember is tightened, thus applying cosine loading and creating axiallydirected forces to the clamp during tightening. The elongate memberpreferably comprises a chain with rollers arranged at the joints betweenadjacent chain links.

Preferably, a spacer device is provided for supporing the tighteningdevice above a V-clamp bolt. The spacer device is designed to be seatedadjacent a joint and extends over a V-clamp on the joint to support thetightening device. In a preferred embodiment of the invention, thespacer device comprises a saddle member having a pair of legs forseating on the tubular sections on each side of a joint, and a saddleportion for straddling the joint above a V-clamp bolt. The tighteningdevice is adjustably mounted on the saddle portion above the joint, andis pivotally secured to opposite ends of the elongate member to tightenthe member around the clamp.

According to another aspect of the present invention a method ofinstalling a V-clamp around a joint is provided, which comprises thesteps of positioning a V-clamp around the joint with its adjusting boltpositioned at the top of the joint, tightening the bolt to maintainorientation around the joint, seating the installation tool over theVclamp bolt and passing the elongate member around the clamp so that itis centered over it, connecting the free end of the member to thetightening device, and repeatedly tightening the member and thentightening the V-clamp bolt until no further tightening is possible. Thetool is then removed from the V-clamp.

BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENT

This present invention will be better understood from the followingdetailed description of a preferred embodiment of the invention, takenin conjunction with the accompanying drawings, in which like referencenumerals refer to like parts, and in which:

FIG. 1 is a perspective view of a typical V-clamp joint;

FIG. 2 is an enlarged sectional view taken on line 2--2 of FIG. 1;

FIG. 3 is a side elevation view of the installation tool mounted on theV-clamp joint;

FIG. 4 is a sectional view taken on the line 4--4 of FIG. 3;

FIG. 5 is a sectional view taken on the line 5--5 of FIG. 4;

FIG. 6 is a sectional view taken on the line 6--6 of FIG. 3; and

FIG. 7 is a top plan view of the structure of FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIGS. 1 and 2 of the drawings show a typical V-clamp 10 joining twoadjacent tubular sections 12 and 14 arranged end to end. The ends of thetubular sections normally overlap as shown in FIG. 2. The V-clampcomprises a ring or sleeve which extends around the joint and has atightening bolt 16 which extends through blocks 18, 20 at adjacent endsof the clamp ring to tighten the clamp around the joint. As shown inFIG. 2, the V clamp has annular V-rims 22, 24 which project into annulargrooves 26, 28 provided adjacent the end of each tubular section 12, 14,respectively. V-clamp joints of this type are used, for example, betweenadjacent tubular missile sections, fuel tanks, on pumps, motors, and onpipeline sections, as well as in many other areas.

The typical V-clamp shown in FIGS. 1 and 2 is normally tightened aroundthe joint by first tightening the bolt 16, then tapping the ring orsleeve with a mallet, and retightening the bolt. This procedure isrepeated until the clamp bolt shows no sign of movement. This techniquehas the disadvantage that the clamp is not evenly tightened around thejoint and may not be seated uniformly. Also, the tapping induces shockand vibration into the tubular sections at the joint and also can reducethe lifetime of the V-clamp ring itself.

FIGS. 3 to 7 of the drawings show an installation tool 30 according to apreferred embodiment of the present invention for installing a V-clampof the type shown in FIGS. 1 and 2 on a joint. The tool 30 basicallycomprises a chain or other elongate flexible member 32 having aplurality of rollers 34 spaced along its length, and a tightening device36 to which opposite ends of the chain 32 are secured for tightening thechain around a V-clamp. The tightening device 36 is spaced above theV-clamp bolt by means of a saddle member 42 which adjustably supports itabove the bolt, as explained in more detail below. The rollers arerotatably mounted on pivot pins 37 securing the adjacent ends ofsuccessive chain links 38, as best shown in FIG. 5.

The tightening device basically comprises a nut member 40 to whichopposite ends of the chain are pivotally secured, as shown in FIG. 6,and a tightening screw 44 which extends through a bore 46 in the centralportion of the saddle member and into a screw threaded bore 48 in thecenter of nut member 40 to suspend it from the saddle member 42. Abushing 45 is mounted between the head of screw 44 and the outer surfaceof saddle member 42.

The link 50 at one end of the chain is releasably secured to the nutmember 40 via a quick release hook 52 at the end of link 54 which ispivotally secured to member 40. Hook 52 engages over the pivot pin 56 atthe end of link 50. The link 55 at the opposite end of the chain isspecially modified to allow access of a hex-drive or similar device fortightening the V-clamp bolt when the tool is positioned over the bolt asshowon in FIGS. 5 and 6. Link 55 is lengthened and formed in two halflinks with a gap 57 between the links to allow access to the hex drive.

The saddle member 42 is arranged to straddle the joint and center theroller chain on the joint. The member 42 has a pair of plate-like legs58,60 having arcuate cut-outs for seating on the adjacent ends of thetwo tubular sections as shown in FIGS. 4 to 6, and a central saddleportion 62 straddling the joint from which the adjusting or tighteningdevice is suspended. The legs 58 and 60 are preferably of unequal lengthas shown in FIG. 5 to allow the saddle to be seated on adjacent tubularsections having different outer diameters. In some types of missilejoints, for example, the tubular sections will have different diameters.A saddle adapter 64 is provided for extending the shorter leg 58 whenthe saddle is to be seated on tubular sections having the same diameter.Adapter 64 comprises an arcuate member with a projection 66 forextending into the gap between the shorter leg 58 of the saddle and theouter face of the underlying tubular section, and a bolt 68 whichextends through aligned openings in adapter 64 and leg 58 to secure theadapter to the saddle. Different size adapters could be provided forvarious tube diameter differences, with the saddle being used with orwithout an adapter according to the relative diameters of the twotubular sections to be joined. In the arrangement shown in FIG. 5, theadapter effectively makes the saddle legs of equal length where theadjacent tubular sections have the same diameter.

A handle 70 projects from the saddle to aid in positioning it above ajoint. The various parts of the installation tool are preferably all ofmetal, although other materials may be used.

In order to statically seat a V clamp using the installation tooldescribed above, the V-clamp 10 is first positioned around the joint sothat the V-clamp bolt 16 is oriented on top of the joint. The V-clampbolt is tightened sufficiently to maintain this orientation. The tool 30is then centered above the V-clamp bolt, using handle 70, so that thelegs of the saddle 42 are seated on the adjacent end sections of thetubes to be joined with the central portion of the saddle straddling thejoint above the V-clamp bolt. The saddle adapter is used if necessary.

At this point the roller chain 32 is wrapped around the joint over theV-clamp ring, and connected to the quick release hook 52 as shown inFIG. 6. The load screw 44 is tightened, raising nut member 40 and thustightening the chain around the clamp ring. Initially screw 44 istightened only enough to maintain its position over the V-clamp bolt,ensuring the roller chain is centered on the V-clamp ring. The loadscrew is then tightened to the desired torque. The V-clamp bolt is thenretightened to its desired torque, using a hex-drive inserted betweenthe saddle legs and through modified end link 55. The tighteningprocedure is repeated until both the load screw and the V-clamp boltindicate no further movement. At this point the installation tool isremoved by disconnecting the roller chain from the quick release hook.The V-clamp will then be fully seated over the joint.

As the load screw is being tightened, drawing up the ends of the rollerchain, the rollers will roll around the circumference of the clamp ring,exerting cosine loading and creating axially directed forces on theclamp which allows the ring to be seated progressively around thecircumference of the joint. As the torque on the load screw isincreased, the force on each roller will be increased and thus theapplied load is distributed evenly around the circunference of the clampring. Since the V-clamp can be fully seated statically using theinstallation tool, shock and vibration loads on installation areeliminated, and the clamp ring does not need to be tapped to ensure thattightening is complete.

This installation tool can be used to seat V-clamps statically aroundany joint, such as joints found between adjacent tubular sections onmissiles, pumps, motors, and hydraulic piping installations, or anywherewhere V-clamps are used in industry.

Although a preferred embodiment of the invention has been describedabove by way of example only, it will be understood by those skilled inthe field that modifications may be made to the disclosed embodimentwithout departing from the scope of the invention, which is defined bythe appended claims.

I claim:
 1. A method of installing a V-clamp around a joint, comprisingthe steps of:positioning a V-clamp around a joint with its adjustingbolt positioned at the top of the joint; tightening the adjusting boltto maintain orientation around the joint; seating an installation toolover the V-clamp bolt and passing an elongate member which is secured atone end to a tightening device of the tool around the clamp so that itis centered over it, and securing the free end of the elongate member tothe tightening device over the adjusting bolt on the top of the joint,the elongate member having transverse rollers spaced along its lengthwhich bear against the outer surface of the V-clamp; repeatedlytightening the tightening device to tighten the elongate member aroundthe V-clamp, and retightening the V-clamp bolt until no furthertightening of either the tightening device or the V-clamp bolt ispossible; and releasing the end of the elongate member and removing theinstallation tool from the V-clamp.